This application relates to a dirt separator for a gas turbine engine formed of separate pieces that can be assembled together in the gas turbine engine such that it can be retrofit into existing gas turbine engines.
Gas turbine engines are known, and typically include a fan section delivering air to a compressor section. The air is compressed and delivered downstream into a combustor section within which the air is mixed with fuel and then combusted to release energy. The products of this combustion process proceed downstream into the turbine and over a set of turbine airfoils, driving the turbine blades to rotate as they extract energy from the flow.
The turbine typically includes a plurality of rotating blades and static vanes. Since the products of combustion are hot, both the blades and the vanes are provided with a thermal protection mechanism involving cooling air. Typically, the cooling air is delivered as a redirected portion of the pre-combustion compressor air into the turbine airfoils. The cooling air structure within both the blades and vanes include relatively small holes in the exterior surface of the airfoils so as to bathe the airfoil in a protective layer of relatively cooler air than the mainstream flow coming from the combustor.
When there are impurities such as dirt or sand in the cooling air, some of these holes can become clogged. This is undesirable as it may prevent the cooling air from adequately protecting the surface of the airfoil. This problem has become particularly acute recently with the increased use of gas turbine engines on aircraft within a desert environment.
New engine designs are often now provided with a dirt separator to address this concern. However, existing gas turbine engines may have cooling air flow passages for that do not easily lend themselves to the installation of a standard dirt separator. Standard dirt separators are generally formed of a single cylindrical, or frusto-conical piece. These separators may be difficult to install into existing gas turbine engines.